Theo Bosboom / Close-up of Emerald damselfly (Lestes sponsa) compound eye, covered in dewdrops, Hatertse vennen, the Netherlands, July.

Paul Bertner / Fly with compound eyes, Khao Yai National Park, Thailand

Alex Hyde / Close-up of Owl Butterfly (Caligo memnon) head showing compound eyes and proboscis. Captive, originating from Central America.

Andy Sands / Robberfly (Machimus cingulatus) head close up showing large compound eyes. Captive, UK, July.

David Maitland / Close-up view of the upward-looking giant dorsal compound eyes of the St Marks fly (Bibio marci) used to detect female flies flying above. Like many insects the eyes are "hairy". Feltwell, Norfolk, UK...

David Maitland / Close-up view of the upward-looking giant dorsal compound eyes of the St Marks fly (Bibio marci) used to detect female flies flying above. Like many insects the eyes are "hairy". Feltwell, Norfolk, UK...

David Maitland / Head of female St. Marks fly (Bibio marci) showing normal sized compound eyes. Feltwell, Norfolk, UK

David Maitland / Head of female St. Marks fly (Bibio marci) showing normal sized compound eyes. Feltwell, Norfolk, UK

David Maitland / Close up of head of a male miniature Blue-winged olive mayfly (Acentrella sp). The male mayflys head is dominated by its remarkable red 'Turbinate' compound eyes which, directed upwards and phenomenal...

Alex Hyde / European hornet (Vespa crabro) head close up showing the three ocelli between the two compound eyes.

Russell Cooper / Common Darter Dragonfly (Sympetrum striolatum) head and compound eyes, South London, UK, September

Alex Hyde / Close-up of compound eyes of unidentified fly {Diptera}. Masoala Peninsula National Park, north east Madagascar.